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[SANET-MG] roundup ready cottn

November 8, 2004

Prof. Joe Cummins

“Roudup Ready Cotton”

This report will deal with the Monsanto’s herbicide tolerant Roundup
Ready Cotton. Like Bollgard II cotton Roundup Ready cotton (rr cotton)
is used for fiber, food and feed. Roundup Ready (rr cotton) was first
marketed in the United States in 1995 followed in later years by Canada,
Japan, Argentina, South Africa, Australia, the Philippines and this year
by China. The report will deal with the makeup of rr cotton and its
impact on humans and the environment.

The herbicide tolerant cotton marketed as rr cotton was originally
derived from two different transformation events of a cotton line called
Coker 312,these events were designated 1445 and 1698. The two events
differed in the chromosomal locus in which they resided and on the gene
sequences inserted at each locus. Currently event 1445 rr cotton is the
primary cotton marketed under the name Roundup Ready Cotton The genetic
makeup of that event originated from a plasmid containg a synthetic
approximation of the glyphosate oxidase (gox) gene driven by . a
modified figwort mosaic virus promoter and terminated by a nos
terminator from Agrobacterium; Followed by another copy of the figwort
mosaic virus promoter driving a synthetic approximation of the CP4 EPSPS
gene derived from Agrobacterium strain CP4, and encodes the enzyme
5-enolpyruvylshikimate-3-phosphate synthase (the primary gene conferring
resistance to glyphosate).A synthetic approximation The EPSPS gene is
used because the bacterial genes are not very active in plant cells. The
synthetic EPSPS sequence is preceded by a chloroplast targeting sequence
from Arabidopsis and the gene is followed by the transcription
terminator gene from Pea. The aad gene from a bacterial transposon ,Tn5
conferring resistance to streptomycin and spectomycin is inserted after
the EPSPS gene bur appears to be inactive in cotton plants. The aad gene
is followed by Kanamycin resistance gene from transposon Tn5 driven by a
Cauliflower Mosaic Virus promoter and terminate d with the nos
terminator from Agrobacterium. In the marketed crop event 1445 lost the
GOX gene and retained the aad gene which was inactive in the plant.
Event 1698 (which is not the primary marketed cotton) is similar to
event 1445 except that it bears an additional EPSPS gene because the
parent plasmid and a partial copy of that plasmid was integrated at one
chromosomal site(1,2,3,4). The DNA events are described as being stably
inherited and the missing gox gene is not a concern to the regulators
nor is the “inactive” streptomycin resistance gene.

Monsanto and the regulators seem to agree that direct human exposure to
the transgenes and their products will be very limited because
cottonseed oil contains very little protein and DNA
(1,2,3,4,).Nevertheless, farm animals consume a great deal of seed cake
and little discussion has been devoted to the impact of transgenic seed
cake on animals and their value as food. Monsanto’s safety assessment of
rr cotton dismissed the possibility that the EPSPS gene and the
transgenic genes including streptomycin resistance and spectomycin
resistance or Kanamycin resistance could participate in horizontal gene
transfer with soil bacteria (1). However, the bacterial marker gene for
Kanamycin reistance in transgenic sugar beet was observed to readily
transform soil Pseudomonas (5) while transgenic potato marker gene
readily transformed soil Actinobacter (6) In both cases the marker
persisted for long periods in the soil bacteria and such bacteria are
capable of exchanging genes with animal pathogens. It is very likely
that the streptomycin resistance marker gene will readily transform soil
bacteria. The suggestion, by Monsanto, that to effectively transform
bacteria the marker genes require co-transformation with a bacterial
promoter gene is not realistic, operator fusions are commonplace in
bacteria showing that the structural gene can be activated by almost any
bacterial promoter. In contrast, the EPSPS gene in cotton is a synthetic
approximation of the bacterial gene from which it originated and has
little homology with the original bacterial gene and bacterial genes in
general and for that reason is unlikely to transform soil bacteria.

Glyphosate applications can be used to control weeds prior to flowering
but glyphosate application after initiation of flowering in rr cotton
reduced pollen viability and seed set with reduced yield (7,8), while
glyphosate application to rr cotton combined with water stress resulted
in abscission of young cotton bolls (9) Use of rr cotton seems to
require irrigation technology and considerable technical savvy.

A additional issue of concern related to use of glyphosate on cotton is
that the herbicide has been shown to move from cotton fabric into and
through human skin (10).

In conclusion, regulators seem to have taken a relaxed attitude to the
somewhat jumbled gene constructions going into GM crops. Fuller
consideration should be given to the synthetic approximations of genes
used in GM crops. Particularly, their recombination and stability, in
that regards relative stability is not adequately determined by
measuring simple Mendelian segregation ratios for a few generations as
has been deemed adequate for GM crops. It seems as if the failure to
label GM foods, feed and fabric has allowed dangerously relaxed release
and promotion of GM crops.


  1. Monsanto Corporation Safety Assessment of Roundup Ready Cotton
     Event 1445 2002 http://www.agbios.com/docroot/decdocs/02-269-008.pdf
  2. United states Food and Drug Administration Monsanto’s glyphosate
     tolerant cotton lines 1445 and 1698 1995
  3. Department of Agriculture Animal and Plant health Inspection
     Service Non-regulated Status for Genetically Engineered Cotton
     line 1445 and 1698 1995
  4. Australia New Zealand Food Authority Draft Risk analysis Report
     Food produced from glyphosate-tolerant cotton line 1445 2000

5. Meier,P. and Wackernagel,W. Monitoring the spread of recombinant DNA
from field plots with transgenic sugar beet plants by PCR and natural
transformation of Pseudomonas stutzeri 2003 Transgenic Research 12,293-304

6. de Vries,J,Heine,M,Harms,K. and Wackernage,W. Spread of Recombinant
DNA by Roots and Pollen of Transgenic Potato Plants, Identified by
Highly Specific Biomonitoring Using Natural Transformation of an
Acinetobacter sp. 2003 Appl Environ Microbiol 69,4455-62

7. Pline,W,Edmisten,K,Oliver,T,Wilcut,J, Wells,R. and Allen,N. Use of
digital image analysis, viability stains,and germination assays to
estimate conventional and glyphosate-resistant cotton pollen viability
2002 Crop Science 42,2193-2200

8. May,O, CulpepperA, Cerny,R,Coots,C,Corkernd,C, Cothrene,J,
Croonb,K,Ferreirab,K, Hartb,J, Hayes,R,Huberb,S, Martens,A, McCloskey,W,
Oppenhuizen,M, Patterson,M,Reynolds,D, Shappley,Z,Subramanik,J,
Wittene,T,York,A. and Mullinix,B. Transgenic Cotton with Improved
Resistance to Glyphosate Herbicide 2004 Crop Sci. 44:234-240

9. Plinea,W, Wells,R, Little,G, Edmisten,K and Wilcut J. Glyphosate and
Water-Stress Effects on Fruiting and Carbohydrates in Glyphosate-Resistant

Cotton 2003 Crop Science 43,879-85

10. Wester,R,Quan,D. and Maibach.H. In Vitro Percutaneous Absorption of
Model Compounds Glyphosate and Malathion from Cotton Fabric into and
through Human Skin 1996 Food and Chemical Toxicology 34,731-5

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